1. Field of the Invention
The present invention relates to an imaging lens and an electronic apparatus having the same, more particularly to an imaging lens with five lens elements and to an electronic apparatus having the same.
2. Description of the Related Art
In recent years, various electronic devices are designed to include imaging lenses and image sensors for image-capturing and video-recording capabilities. To improve portability and imaging performances while reducing dimensions and weights of the electronic devices, different combinations of lenses are installed in the electronic devices.
U.S. Pat. Nos. 6,476,982 and 7,453,654 disclose imaging lenses with four lens elements, which are generally operated at high F numbers (i.e., small apertures) to thereby alleviate impact to image quality by marginal rays that cannot be focused onto the image sensors, which is known as optical vignetting. However, such a technique to improve image quality also reduces the amount of incident light sensed by the image sensors, which in turn reduces signal-to-noise ratios of captured images. Therefore, the aforementioned technique is inappropriate for application to electronic devices with image sensors having relatively small pixel sizes.
U.S. Pat. Nos. 7,480,105, 7,110,188, 7,443,610, and 7,710,665 disclose imaging lenses with five lens elements to alleviate the drawbacks of those with four lenses. Each of the imaging lenses has a unique combination and arrangement of lens elements with different shapes to thereby achieve a specific combination of optical characteristics. However, in achieving the specific combination of optical characteristics, certain aspects of optical performance are compromised. Therefore, the need to develop other imaging lenses with better combinations of optical characteristics still exists in the market.